1. Technical Field.
This invention relates to trailers for towing vehicles. In particular it relates to a collapsible trailer for towing a vehicle which utilizes a standard towing dolly as its wheel base.
2. Background Art.
The most common method of towing an unmanned automobile is to use a tow truck which lifts one end of the car, disengaging from the ground one of the two sets of wheels of the automobile, and therefor allows the tow truck to turn a corner without skidding the towed vehicle around the corner. This method works providing that one has access to a tow truck and that the vehicle to be towed is able to be lifted and held during towing.
Front wheel drive vehicles, however, pose a unique problem to the tow truck operator in that a large percentage are unable to be lfited at their front end by the standard tow truck lifting apparatus without causing damage to the vehicle. This is because many of the front wheel drive vehicles have power train assemblies which are incompatible with standard tow truck lifting and towing rigging. Additionally, many front wheel drive vehicles cannot be towed backwards because of either of two reasons, the first being that the drive train may be damaged as a result of being towed backwards, and secondly in the event that the reason the vehicle is being towed is because it has been impacted from the front thereby making the front wheel assembly not operable. A special and very expensive hydraulic apparatus has beem employed to lift front wheel drive vehicles by their front wheels so as not to cause damage to the drive train. Because the hydraulic apparatus is so expensive, many tow truck operators cannot afford it and consequently cannot efficiently tow front wheel drive vehicles.
As a result current practice is that the tow truck owner must resort to the use of a vehicular trailer of some sort. Unfortunately, a towing trailer cannot be towed behind the two trucks since, in the event, that the towing trailer is not used, it will interfere with towing operation. Likewise, the tow truck operator cannot carry a standard vehicle trailer on the tow truck because, quite simply, it is too heavy and bulky for one, or even two people to hoist or place into a storage position. Another alternative currently available is the purchase of a specialized tow truck which functions in a completely different manner from the standard tow truck in that it is a sophisticated, hydraulically raised, ramp type truck bed and winch assembly wherein the back end of the ramp is lowered to receive the disabled vehicle, which is then hoisted up onto the ramp. After being towed onto the ramp, the hydraulicaly operated ramp is returned to a horizontal position and the disabled vehicle is, for all practical purposes, loaded onto a truck bed for transport. This type of a tow truck is very expensive and cannot be easily used in all of the varied applications that may be required.
What is needed is a collapsible vehicular trailer that can be conveniently stored upon a standard tow truck, and preferably, which incorporates and utilizes the standard towing dollies normally and routinely carried by standard tow truck operators.
Another application for this particular invention is found in the use of standard service trucks as opposed to tow trucks. Many repair shops, particularly those along major highways, operate repair trucks in conjunction with tow trucks. These repair trucks carry various automotive parts and supplies such as spark plugs, fan belts, gasoline, and the like. If the operator of a disabled vehicle were to call a service station operating a service truck, and when the service truck operator responds to the scene of the disabled vehicle, the serviceman discovers, that a repair cannot be made at that location, then, using currently available equipment, the service truck operator would have to call for a tow truck. If, however, a collapsible vehicular trailer such as that disclosed in the present invention were to be carried upon the service truck, then it would be a simple matter to assemble the vehicle trailer to facilitate towing the disabled vehicle to the automotive service center.
There are other cases wherein a person might want to tow a vehicle who does not have access to a tow truck, such as towing a second vehicle behind a motor home, where the second vehicle is a front wheel drive automobile. The lift mechanism provided by a recreactional vehicle towing mechanisms in common use today are not suitable for front wheel drive vehicles.
Denny, U.S. Pat. No. 3,653,680, teaches a tow trailer with a folding carrier platform. When the trailer is not in use, the platform folds up so as to decrease the overall length of the trailer. Denny also teaches rear mounted wheels which swivel independently, very similar to casters. The biggest problem with the Denny device is that is can not be broken down easily for storage when not in use and must be pulled intact to transport it to the towed vehicle.
Roberts, U.S. Pat. No. 3,674,167, discloses a vehicle ambulance adapted to receive and transport disabled vehicles. Roberts teaches a basic platform trailer having four wheels which are spaced closely together to enable turning. A disabled vehicle is winched up onto the trailer platform by an electric winch and is then secured for transporting. The disadvantages to the Roberts device are that it must be transported intact to the site and is not collapsible to provide for convenient storage and transportation.
Accordingly, it is an object of this invention to provide a collapsible vehicular trailer which can be conveniently stored and transported and uses a standard, collapsible towing dolly as its wheel base. Another object of the present invention is to provide a simple apparatus which can be attached to a standard trailer hitch ball for towing front wheel drive vehicles.